Text

Exam Rept 50-264/OLS-87-01 on 871201-02.Exam Results: Candidate Passed
	ML20237E152
Person / Time
Site:	Dow Chemical Company
Issue date:	12/22/1987
From:	Burdick T, Hare E; NRC OFFICE OF INSPECTION & ENFORCEMENT (IE REGION III)
To:	;
Shared Package
ML20237E150	List: ML20237E148; ML20237E152;
References
	50-264-OLS-87, 50-264-OLS-87-0, NUDOCS 8712280183
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U.S. NUCLEAR REGULATORY COMMISSION REGION III Report No. 50-264/0LS-87-01(DRS)

Docket No. 50-264 License No. R-108 Licensee: Dow Chemical Company 1803 Building Midland, MI 48640 Facility Name: Dow Chemical Company Examination Administered At: Holiday Inn, Midland, Michigan Dow Chemical, Midland, Michigan Examination Conducted: December 1-2, 1987 Examiner: Elizabeth A. Hare ch -

M Date, Approved By: Thomas M. Burdick I L!t Chief, Operating Licensing Section Date Examination Summary Examination administered on December 1-2, 1987 (Report No. 50-264/0LS-87-01(DRS))

to one Senior Reactor operator candidate.

Results: The candidate passed.

8712280183 871223 PDR ADOCK 05000264 V PDR

, a REPORT DETAILS

1. Examiners E. A. Hare, Chief Examiner

2. Exit Meeting On December 2, 1987 at the conclusion of the examination, a meeting was held to discuss generic findings made during the course of the examination.

The following personnel attended the meeting:

Facility Representative C. W. Kocher, Reactor Supervisor NRC Representative E. A. Hare The item discussed during this meeting is listed in the following paragraph.

a. Two instances were observed where facility personnel placed their ungloved hands into the reactor pool. The examiner noted that l placing one's hand into the reactor pool without a glove was not a good radiation practice since the water is potentially contaminated.

This practice shculd be observed and revised as appropriate.

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3. Examination Review Refer to the Attachment.

Attachment Question J. 03 Facility Comment:

The CONSOLE POWER switch controls primary AC power to all circuits except four circuits. State 3 of the 4 circuits it does not power. (Dow Chemical General Description, Section 2.3.1)

The General Description, Section 2.3.1, is not up to date. The correct answers to this question are

1. High-voltage power supply (water radiation monitor)

2. Water monitor GM Counter Circuit (amplifier and count-rate-meter)

3. Water temperature circuits

4. Wide Range Log Power Channel

5. Water Conductivity Bridge

6. Two-pen Recorder

7. Area Monitor Readout

8. Percent Power Channel

9. Linear Power Channel

10. Audible Channel NRC Response:

Agree with comment. Will accept any of the above mentioned circuits. Answer key will be changed to reflect alternative answers.

Question J.09 Facility Comment:

Question J.09: a. What type of neutron sources are used at Dow TRIGA?

Answer: Americium-241-berylium, polonium-berylium (Dow Chemical General Description, Section 1.4.3)

Section 1.4.3 states, "Two types of neutron sources may be used." (emphasis supplied). Afteralongdiscussionoftgitwotypesofsourcesthesectign concludes with the statement, "Our 2 Ci Am-Be source yielded 5.28 x 10 n/sec on 4-2-1968."

To add to the confusion, the original source g2 s a Po-Be source, which was replaced in 1968 with the 410-day half-life Am-Be source which is still in use.

NRC Response:

Agree with comment. The answer key will be changed to reflect the use of one source. Point values will also be changed to reflect this change.

Question H.07b.

NRC Initiative:

-The coefficient value for Stainless Steel was added as an alternate answer for the temperature coefficient.

L ..

MASTK COPY U. S. NUCLEAR REGULATORY COMMISSION SENIOR REACTOR OPERATOR LICENSE EXAMINATION FACILITY: DOW CHEMICAL REACTOR TYPE: IRIGA DATE ADMINISTERED: 87/12/01 EXAMINER: H6RE. E. A.

CANDIDATE INSTRUCTIONS TO CANDIDATE:

Use separate paper for the answers. Write answers on one side only.

Staple question sheet on top of the answer sheets. Points for each question are indicated in parentheses after the question. 'The passing grade requires at least 70% in each category. Examination papers will be picked up six (6) hours after the examination starts.

% OF CATEGORY % OF CANDIDATE'S CATEGORY VALUE_ TOTAL SCORE _VALUE. CATEGORY 20.00 20.15 _ H. REACTOR THEORY 20.00 20.15 I. RADIOACTIVE MATERIALS HANDLING DISPOSAL AND HAZARDS 20.00 __20.15 J. SPECIFIC OPERATING CHARACTERISTICS 19.50 19.65 K. FUEL HANDLING AND CORE PARAMETERS 19.75 19.90 L. ADMINISTRATIVE PROCEDURES, ,

CONDITIONS AND LIMITATIONS 99.25 % Totals Final Grade All work done on this examination is my own. I have neither given nor received aid.

Candidate's Signature

NRC RULES AND GUIDELINES FOR LICENSE EXAMINATIONS During the administration of this examination the following rules apply:

1. Cheating on the examination means an automatic denial of your application and could result in more severe penalties.

2. Restroom trips are to be limited and only one candidate at a time may leave. You must avoid all contacts with anyone outside the examination room to avoid even the appearance or possibility of cheating.

3. Use black ink or dark pencil only to facilitate legible reproductions.

4. Print your name in the blank provided on the cover sheet of the examination.

5. Fill in the date on the cover sheet of the examination (if necessary).

6. Use only the paper provided for answers.

7. Print your name in the upper right-hand corner of the first page of each section of the answer sheet.

8. Consecutively number each answer sheet, write "End of Category __" as appropriate, start each category on a new page, write only on one side of the paper, and write "Last Page" on the last answer sheet.

9. Number each answer as to category and number, for example, 1.4, 6.3.

10. Skip at least three lines between each answer.

11. Separate answer sheets from pad and place finished answer sheets face down on your desk or table.

12. Use abbreviations only if they are commonly used in facility literature.

13. The point value for each question is indicated in parentheses after the question and can be used as a guide for the depth of answer required.,

14. Show all calculations, methods, or assumptions used to obtain an answer to mathematical problems whether indicated in the question or not.

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15. Partial credit may be given. Therefore, ANSWER ALL PARTS OF THE QUESTION AND DO NOT LEAVE ANY ANSWER BLANK.

16. If parts of the examination are not clear as to intent, ask questions of the examiner only.

17. You must sign the statement on the cover sheet that indicates that the work is your own and you have not received or been given assistance in i completing the examination. This must be done after the examination has been completed. !

I

, a.

18. When you complete your examination, you shall:

a. Assemble your examination as follows:

(1) Exam quections on top.

(2) Exam aids - figures, tables, etc.

(3) Answer pages including figures which are part of the answer.

b. Turn in your copy of the examination and.all pages used to answer the examination questions,

c. Turn in all scrap paper and the. balance of the paper that you did not use for answering the questions,

d. Leave the examination area, as defined by the examiner. If after leaving, you are found in'this area while the examination is still in progress, your license may be denied or revoked.

k

. '.H. REACTOR THEORY Page 4 QUESTION H.01 (2.00)

a. Explain what the difference is between k-infinite and k-effective.

(1.0)

b. K-effective of a reactor is given as 1.0795 delta k/k. What k-excess does the reactor have. (0 5)

c. What reactivity is associated with this k-effective? (0.5)

QUESTION H.02 (1.50)

a. What is the purpose of the'" moderator" in the reactor? (1.0)

b. Indicate which one of the following is considered an important'aspec" of a good moderator. (0.5) ,

(1) Low mass number (2) barge absorption cross-section (3) Small scattering cross-section QUESTION H 03 (2.00)

Define the following term:

1. ALBEDO (1.0)'

2. What is this term dependent on? (1.0)

QUESTION H 04 (1.50)

Indicate whether the following statements are TRUE or FALSE. (1.5)

a. The delayed neutron fraction is greater at BOL'than at EOL. (.75)

b. When determining reactor period, the delayed neutron term may be considered insignificant if reactivity added is less than beta and the prompt term may be considered insignificant when the reactivity added is greater-than or equal to beta. (.75)

(***** CATEGORY H CONTINUED ON NEXT PAGE *****)

', H.' '

REACTOR THEORY Page 5 QUESTION H.05 {3.00) j Briefly explain the difference between:

a. Fast and prompt neutrons. (1.0) l b.

Slow and delayed neutrons. (1.0)

c. Activity and reactivity. (1.0)

QUESTION H.06- (2.00)

a. A step insertion of a small amount of positive reactivity is made to a reactor while critical in the very low power range. Describe the changes in neutron' flux'after the reactivity addition. (Neglect heating effects.) (1.0)

b. Describe the changes in neutron flux following a reactor scram from full power operation. (1.0)

QUESTION H.07 (2.00)

a. List the two major negative. reactivity coefficients that can halt th rapid power escalation following a positive step reactivity insertion. (1.0)

b. What are their values? (1.0)

QUESTION H.08 (3-.00)

a. What is the major fission product poison in your reactor? (1.0)

b. How is it produced? (Include pertinent half-life.) (1.0)

c. How is it removed? (Include pertinent half-life.) (1.0)

(***** CATEGORY H CONTINUED ON NEXT PAGE *****)

H. ' REACTOR THEORY Page 6 QUESTION H.09 (1.00)

Fill in the Blanks. (1.0)

a. The equilibrium concentration for the Xe is reached after about hours of steady state operation.

b. Whenever a reactor is shut down, xenon rapidly builds up, reaching a peak after about hours.

QUESTION H.10 (2.00)

As reactor power increases, how does this effect the fuel and reactor power?

(***** END OF CATEGORY H *****)

. I. RADIOACTIVE MATERIALS HANDLING DISPOSAL Page 7 AND..H&LABRE QUESTION I.01 (2.50)

Define the following terms:

a. Radioactivity (0.5)

b. Contamination (0.5)

c. Dose (0.5)

d. Maximum Permissible Exposure (MPE) (0.5) .

e. Half-thickness (0.5)

QUESTION I.02. (3.50)

Answer the following in accordance with 10 CFR 20.

a. What three conditions must be satisfied'to permit whole body radiation exposure in excess of 1.25 rems per quarter? (3.0)

b. What is the legal limit for skin exposure to individuals less than 18 years of age? (0.5)

QUESTION I.03 (1.50)

A material decays at a rate of 35 percent per day, what is its half-life?

(1.5) ..

QUESTION I.04 (3.00)

Radioactive isotopes that are common from the operation of-a research reactor are N-16 and A-41. (3.0)

a. For each of the above,.give the source (i.e. explain how it is produced), where it would be found at DOW TRIGA' reactor, and the half-life. (.33.each, total 2.0)- 3

b. What, if any, precautions or design attributes are taken to reduce i the-effect of these isotopes at Strd Nuclear--Reactor? (1.0)

DO Y K'A ,

i l

(***** CATEGORY I CONTINUED ON NEXT PAGE *****)

. LbD196CTIVE MATEB1ALS HANDLlHG DISPOSAL Page 8 AND HAZARDS QUESTION I.05 (1.50)

How long can a person stay in an area where the meter reading is 500 r/hr for life saving reasons? (Permissible exposure time)

QUESTION I.06 (2.00)

Does the biological effect of 100 rem depend on whether it is a neutron o gamma dose? Explain.

QUESTION I.07 (2.00)

List the three distinct types of areas where ALL'Special Nuclear Material-present at the Dow Chemical Midland location shall-be kept, maintained, used, or stored.

QUESTION I.08 (1.00)

Fill in the Blanks:

Transfer of Special Nuclear Material from and to any of the storage facilities shall be carried out only with the authorization o.t (1) and in the presence of th,e (2) .

QUESTION I.09 (2.00)

For the following radiation monitoring instruments, choose the proper ionization radiation that'it detects and measures.

1. Victoreen 488A: portable survey meter a. Alpha, beta, gamma, neutron

2. Victoreen 855: area monitor b. Alpha, beta, gamma i

3. Victoreen 440: survey meter c. beta, gamma

4. Geiger-Mueller: survey meter d. gamma

e. Neutrons: fast or thermal

(***** CATEGORY I CONTINUED ON NEXT PAGE *****)

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L RADIOACTIVE MATEBIALS HANDLING DISEQShL Page 9 hBD BhZhBDS QUESTION I.10 (1.00)

What two people have the responsibility to determine the classification os waste generated in the neutron activation area?

i 1

(***** END OF CATEGORY I *****)

J. SPECIFIC OEEPATING CBAFACTERISTICS 'Page 10 QUESTION J 01 (2.25)

The water purification system serves three functions. State the three.(3:

functions.

QUESTION J.02 (1.50)

Explain how the cooling system prevents siphoning.of the reactor pool should a leak in the system develop.

QUESTION J.03 (1.50)

The CONSOLE POWER switch controls primary AC power to all circuits except four circuits. State 3 of the 4 circuits it does not power.

QUESTION J.04 (2.25)

When using the rotary specimen rack, there are three considerations regarding the effect or nature of the sample when introducing the sample into the reactor. State the three (3) considerations.

QUESTION J.05 (2.00)

State the four (4) bistable trip circuits provided by the. Wide Range-Log-Powe r Channel .

(***** CATEGORY J CONTINUED ON-NEXT PAGE *****)

J. SPECIFIC OPEBATING CHARACTERISTICS Page 11 QUESTION J.06 (3.00)

For the conditions given below, explain the " significance" of each of the combinations (i.e. what problems do these indicate to the operator).

LIGHTS UP DN CONT /ON CONTROL ROD AND DRIVE

a. OFF ON OFF Rod and Drive completely down (1.0)

b. ON OFF OFF Drive completely up, rod down, ~

no magnet contact (1.0)

c. OFF OFF ON After dropping rod (scram) normal operation would give OFF, OFF, OFF (1.0)

QUESTION J.07 (1.00)

There are interlocks in the UP pushbutton circuit that make the circuit' inoperative under certain conditions. State these interlocks.

QUESTION J.08 (3.00)

When using the Flux Controller in the automatic mode, there are three ranges of operation. State these three ranges [1.5] and explain how the control rods are controlled for each range [1.5). (3.0)

QUESTION J.09 (2.00)

a. What type of neutron sources are used at Dow TRIGA7 (1.0)

b. What are the advantages and/or disadvantages of the sources? (1.0).

QUESTION J.10 (1.50)

In designing the reactor well, aluminum was. selected instead of steel, fo; the tank material for what reasons? (Two reasons required)

(***** END OF CATEGORY J *****)

K .' FUEL HANDLING AND CORE PAB& METERS Page 12

, QUESTION K.01 (2.00)

What conditions constitute the minimum shutdown margin with fixed experiments in place as defined in TRIGA Tech Spec.?

(Include value)

QUESTION K.02 (1.00)

How often do the fuel elements have-to be visually inspected? (0.5)

How often do the control elements have to be' visually inspected? (0.5)

QUESTION K.03 (1.00)

How (1.0) much excess reactivity is permitted by the Technical Specifications?

QUESTION K.04 (3.00)

Dow Chemical Tech Spec Section F,

" Control and Safety Systems," lists four tests which shall be performed at least semi-annually.

tests and the exception to the semi-annual requirement. List the four (4)

QUESTION K.05 (1.50)

What is the difference between the regular fuel elements and dummy fuel elements? (i.e., what does each one consist of.)

QUESTION K.06 (2.00)

Your facility Tech. Specs.

apply to all experiments. places two limitations on reactivity which State the two (2) limitations.

(***** CATEGORY K CONTINUED ON-NEXT PAGE *****)

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K. FUEL __ HANDLING AND CORE PARAMETERS Page 13 QUESTION K.07 (3.00)

Fill.in the blanks:

The following sentences deal with procedure 4.3.3.4, " Loading of Reactor Core."

A (1) must be present during core loading operations.

The neutron source must be present in (2) position before fuel loading can be initiated and must remain in the core during all loading and unloading operations.

For initial load, all rods are initially banked in the (3) position while at a later stage of the-loading procedure the shim rod is left in its (4) position.

The initial batch of 18 elements is loaded in the (5) and (6) rings.

QUESTION K.08 (2.00)

List two requirements in your Technical Specifications which apply to fue storage at your facility.

QUESTION K.00 (4.00)

Fuel cladding failure is suspected. What steps are to be taken to determine if the cladding.has failed and if so, its location? ,

(***** END OF CATEGORY K *****)

I -

L. ADMINISTRATIVE PROCEDURES CONDITIONS Page 24 AND... LIMITATIONS QUESTION L.01 (2.00)

What condition constitutes immediate telephone report to the NRC followed by a written report within ten days?

QUESTION L.02 (3.00)

During reactor operations, a disagreement arises between you and the. .

experimenter regarding the safety of the. operations. What actions shoul(

be taken? (Consider all resolutions) '

j QUESTION L.03 (3.00)

The following questions are in reference to the Reactor Operations Log Book.

a. What items are required to be included in a log book entry pertainig to a specific event? (Four items required) (2.0)

b. How will entries pertaining to fuel changes be designated? (0.5)

c. How will entries pertaining to all other core changes be designated?

(0.5)

QUESTION L 04 (1.00)

What are the staffing requirements when the reactor is operating?

QUESTION L.05 (3.00)

The reactor operator must complete, except during continuous runs, the Reactor Startup Checklist (4-13) before.each day's reactor operations has begun. What does completion of this checklist ensure? -(Three items required) (3.0)

'(***** CATEGORY L CONTINUED ON NEXT PAGE *****) {

L, ADMINISTRATIVE PROCEDURES. CONDITIONS Page 15 AND LIMITATIONS l

i QUESTION L.06 (2.25)

In order to attain the objective of the TRIGA reactor, safety of operatio; is of paramount importance. The requirement for safety is threefold.

State these three (3) requirements.

QUESTION L.07 (2.00)

a. Who can activate the Emergency Response System? (0.5)

b. There are three methods of activation for the Emergency Response System. State the three (3) methods. (1.5)

QUESTION L.08 (1.50)

List the three (3) emergency classifications'for your facility in order of severity, least severe first.

QUESTION L.09 (2.00)

The following Fill In The Blank question is in regards to the Dow Chemica:

Reactor Operator Requalification Frogram; Each licensed operator shall operate the reactor at least once every

[1.0] and shall perform a minimum of changes during each calendar year.

[1.0) reactivit)

(***** END OF CATEGORY L *****)

(********** END OF EXAMINATION **********)

____________--_-Y

^

EQUATION SHEET f = ma y = s/t Cycle efficiency = (Network out)/(Energy in) a = ag s = Vot + 1 atg E = ac2 KE = 5 mv2 a = (Vf - Vo)/t A = AN A = Ane-At PE = agh Vf = Vo + at w = e/t x = in2/tg = 0.693/tg W = .6 tgeff = [(tg) (tb)3

[(tg) + (t b)3 AE = 931 Am y , 3 ,-Ix 0

Q = 51Cpat 6 = UAat I = Ice *

i Pwr = Wfah I = Io 10-x/TVL TYL = 1.3/p P = Pc 10sur(t) HVL = -0.693/9 l

P = Po et/T SUR = 26.06/T SCR = S/(1 - Keff)

CRx = S/(1 - Keffx)

SUR = 25p/t* + ( a - p )T CRj (1 - Keff1) = CR 2 (1 - keff2)

T = (t*/p) + [(6 - p)/Ip] H = 1/(1 - Keff) = CR1/CRo T = 1/(p '6) M = (1 - Keffo)/(1 - Kefft)

. T = (6 - p)/(Ap) , SDM = (1 - Keff)/Keff p = (Keff-1)/Keff = AKeff/Keff f* = 10-5 seconds I = 0.1 seconds-1 p = [(1 /(T Keff)] + [ieff/(1 + IT)) ~

'l dit=1d22 2

P = (IeV)/(3 x 1010) 11d1 2=1d22 I=N R/hr = (0.5 CE)/d2(meters)

R/hr = 6 CE/d2 (feet)

Water Parameters Miscellaneous Conversions 1 gal . = 8.345 lbm. I curie = 3.7 x 1010dps 1 gal. = 3.78 liters 1 kg = 2.21 lbm 1 ft3 = 7.48 galt . I hp = 2.54 x 103 Btu /hr Density = 62.4 Ibm /ft I sw = 3.41 x 106 8tu/hr Density = 1 gm/cm3 1 in = 2.54 cm Heat of vaporization = 970 Btu /1bm 'F = 9/5'C + 32 Heat of fusion = 144 Btu /1bm 'C = 5/9 ('F-32) 1 Atm = 14.7 psi = 29.9 in. Hg. 1 BTU = 778 ft-1bf 1 ft H 2O = 0.433 lbf/in2

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H. REACTOR THEORY Page 16 ANSWER H.01 (2.00) ,

a. K-infinite is the multiplication constant for a theoretical reactor with zero leakage.

due to slow and fastK-effective takes=into leakage (k-eff k-infaccount neutrons

slow and fast lost non-leakage probability.) (1.0) b.

K-excess = k-effective-1 = 1.0795-1 = 0.0795 delta k. (0.5) c.

Reactivity : (k-effective-1)/k-effective : (1.0795-1)/1.0795 =

0.0736 delta k/h. (0.5)

REFERENCE '

Dow Chemical Reactor Physics and Kinetics, Section 6 1.9, 6.2.1 l

ANSWER H.02 (1.50) a.

Neutrons of low energy have the highest probability of causing fission in the fuel. Most neutrons are born at high energy levels.

The moderator reduces the neutron energy level. (1.0)

b. (1) Low mass number (0.5)

, REFERENCE Dow Chemical Reactor Physics and Kinetics, Section 6.1.10 ANSWER H.03 (2.00) 1.

The to theratio of theentering number numberthe of neutrons reflector. reflected back into the reactor 2.

The value of ALBEDO will depend on the composition [0.5] and thickness [0.5) of the reflector. (1.0)

REFERENCE Dow Chemical Reactor Physics and Kinetics, Section 6.1.11

(***** CATEGORY H CONTINUED ON NEXT PAGE *****)

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H. REACTOR THEORY Page 17 ANSWER H.04 (1.50)

a. True

b. False REFERENCE Dow Chemical Reactor Physics and Kinetics, Sections 6.2.5, 6.2.9, 6.2.10 ANSWER H.05 (3.00)

a. Fast neutrons refer to those at high energy levels. (0.5)

Prompt neutrons refer to those released at the time of fission.

(0.5)

b. Slow neutrons are neutrons at low energy levels. (0.5)

Delayed neutrons are those which appear at some time after the fission event due to fission product decay. (0.5)

c. Activity refers to the rate of radioactive decay. (0.5)

Reactivity expresses the deviation of a reactor from the critical

condition. (0.5)

(Exact wording not required)

REFERENCE Dow Chemical Reactor Physics and Kinetics, Section 6.2 ANSWER H.06 (2.00) -

a. There is a " prompt jump" increase in neutron flux due to the immediate effects of prompt neutrons. (0.5) Power then increases ot a stable period the value of which is determined by the amount of reactivity inserted and the-delayed neutron generation time. (0. 5)

b. .Following a scram, there is a prompt drop in neutron flux as prompt neutron generation is stopped. (0.5) Flux then gradually. decreases as delayed neutrons continue to be generated from the decay of the precursor groups. (0.5)

(***** CATEGORY H CONTINUED ON NEXT PAGE *****)

H. ' REACTOR THEORY Page 18 REFERENCE Dow Chemical Reactor Physics and Kinetics, Sections 6.2.9, 6.3.7 ANSWER H.07 (2.00)

a. Void coefficient (0.5)

Temperature coefficient (0,5)

b. -2 x 10E-3 delta k/k/1% water void (0.5)

-9.7 x 10E-5 delta h/k/ degree C (0. 5)DE l9.1 % ID

_ 5- g 3' (coefficient values must be within 20% of actual value)- .

REFERENCE Technical Specifications, Appendix B, Sections 6.3.4, 6.3.8 ANSWER H.08 (3.00)

a. Xenon 135 (1.0)

b. (1) Directly from fission. (.25)

(2) From beta decay of fission products-iodine-135 and tellurium-135. (0.375) Tellurium-135 decays to iodine-135 (19 seconds half-life - 2 min. per Dow Chemical Reference) whict then decays to xenon-135 (6.7 hour8.101852e-5 days 0.00194 hours 1.157407e-5 weeks 2.6635e-6 months half-life). (0.375)

c. (1) Burnout by neutron absorption. (.333)

(2) Beta decay to cesium-135 (0.333) with a 9.2 hour2.314815e-5 days 5.555556e-4 hours 3.306878e-6 weeks 7.61e-7 months half-life.

(0.333) *

(Exact half-life not required, must be within 50% of actual half-life)

REFERENCE Dow Chemical Reactor Physics and Kinetics, Section 6.3.11 ANSWER H.09 (1.00)

a. 40 hours4.62963e-4 days 0.0111 hours 6.613757e-5 weeks 1.522e-5 months +/- 5 hours5.787037e-5 days 0.00139 hours 8.267196e-6 weeks 1.9025e-6 months . (0.5)

b. 5 to 7 hours8.101852e-5 days 0.00194 hours 1.157407e-5 weeks 2.6635e-6 months . (0.5)

(***** CATEGORY H CONTINUED ON NEXT PAGE *****)

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H. REACTOR THEORY Page 19 REFERENCE Dow Chemical Reactor Physics and Kinetics, Section 6.3.11 ANSWER H.10 (2.00)

As power increases, both the fuel and the moderating material in the fuel element simultaneously heat up [1.0]. Immediately, the fuel becomes less effective [0.5] (due to a.large prompt negative temperature coefficient) causing reactor power to return automatically [0.5).

REFERENCE Dow Chemical General Description, Section 1.1

(***** END OF CATEGORY H *****)

_ _ _ _ _ _ --____--_-_--_-____D

I. RADIOACTIVE MATEBIALS HANDLING DISPOSAL Page 20 AND HAZARDS i

ANSWER I.01 (2.50)

a. Radioactivity

,l That property of a substance which causes it to emit ionizing ;

radiation. This property is the spontaneous transmution of the atoms of the substance.

1

b. Contamination An impurity which pollutes or adulterates another substance. In radiological safety, contamination refers to the radioactive materials which are the sources of ionizing radiations.

c. Dose 1

The quantity of radiation absorbed per un<t a i by the body or by any portion of the body.,

d. Maximum Permissible Exposure (MPE) !

The greatest whole body radiation dose permitted an individual in I a given circumstance. I

e. Half Thickness i

The thickness of a material which will reduce a gamma flux by a -l factor of two.

(Exact wording not required for full credit)

REFERENCE Dow Chemical Radiation Safety, pgs. 1-4, 49 ANSWER I.02 (3.50) I

a. Quarterly dose less than 3 rems Lifetime dose less than 5fN-18) I Accumulated occupational exposure is documented on NRC Form 4 (3 @ 1.0 pts each = 3.0)

b. .75 rems per quarter

(***** CATEGORY I CONTINUED ON NEXT PAGE *****)-

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5 I. RADIOACTIVE MATERIALS HAMdLING DIS??S6L Sago 21 AND HAZARDS I c. T '\

c.

P w )

L 1 ( ..' ./'

REFERENCE ,'.- '

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<>1 10 CFR 10.101 and 104 x

1 f. ,

y il i !

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g{

x '

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ANSWER I.03 a i t .(50f N = Noe[-lambia*t) {

100 - 35 / 100:T e[-lambda x 1] '

O.65 ,e [-lambda x 1] 'g in 0. 65' :. -lambda

9Q 0.43 =.<1ambda s.-

T1/2 = 0.693 / lambda T1/2 = 0.693 / 0.43 = 1,61 (day) -

i v ..

REFERENCE ) ;)

l l Dow Chemical Reactor Theory Section', pgs. 6.2.7, 6.2.8

. 1

% 1 ANSWER I.04 (3.00) ^.

'(

T ,s,,,

)

a. 0-16 [n. p] N-16;' coolant water; '

7. seconds '*"

g

',7 j m

,4 A-40 + (n, gtLuifaf A- 41; air space near reactor (baam' ports ant.-

., radiation facQ ity) and primary water with dissolvej' air; l'E hours (Exact half dife not required, must be within 50*' of artwpl half-lifel; .s ~

l *p

(,33 each', total 2.0) '

~,,..

b. N-16 : Long trcpspo"rtation time from reactor core'to surface of shielding yaten p ,(1. 0 ) ,

R4FERENCE ' '

Dow Chemical R Ciation'Sofety Section 5.3.7 v a N

d3

.(

<s ANSWER I.05 (b.50)

LifeSaviagylvasureLimitir,200r

<3 r s

(.75) <

200r/500r/hr'=.4hror2gainutes .!

s (.7%)

s

'l ,

/ s - ,\ Yi., <N l' , s

.h

%j\

s 6*

e -

go

+ + , ,

\

(***** CATEGORY I CONTINUED ON NEXT. PAGE ***** ) J

, A9'

+

o i ti, ~g'],.

s

.s a\

a+

\y -

,. A

L R6DLQACTIVE_.iBTERIALS HANDLILG DIEPOSAL Page 22 6HD BAL6RDn REFERENCE Dow Chemical Radiation Safety, Section 5.1.5 ,'

ANSWER I.06 (2.00)

No (1.0). The unit REM already considers the different effects. Ram is biological unit, thus differed. radiation causing the same dose in REM should have the same effect. l'.0)

REFERENCE 10 CFR 20 ANSWER I.07 (2.00)

1. Pool of the TRIGA reactor

2. Storage wells in the floor of the reactor room.

3. Two radiation caves

( 3@ .66 each : 2.0) ,

REFERENCE Dow Chemical Administrative Procedures 3.4.3 ANSWER I.08 (1.00) .

(1) Health Physics (0.5)

(2) Reactor Supervisor (0.5) l REFERENCE Dow Chemical Administrative Procedures 3.4.3 i

s 4

(***** CATEGORY I CCNTINUED ON NEXT PAGE *****)

__ _ ._ __ _ .- _ J

~ %. ..

. ,f

I. ' RADIOACTIVE MATERIALS HANDLING DISPOSAL Paae 23-AND HAZARDS-ANSWER I.09- (2.00)

1. e.

2. d.

3. c.

4. .b.

j (4 @ 0.5' pts each = 2.0)

REFERENCE Dow Chemical Radiation Safety' Sections 5.4.1, 5.4.2 -

ANSWER I.10 (1.00)

1. Experimenter

2. Senior Reactor Supervisor (2 @ 0.5 pts each = 1.0)

REFERENCE Dow Chemical Proedures 4

l l

l

!^'

l . j, l

(***** END OF CATEGORY I *****)

J, SPECIFIC OPERATING CEARACIEBISTICS Page 24 ANSWER J.01 (2.25)

1. Maintains low electrical conductivity of the water to minimize corrosion of all reactor components, particularly the fuel element cladding.

2. Reduces radioactivity in the water by removing nearly all particulat<

materials and ions in solution.

3. Maintains the optical transparency of the water and avoids buildup of algae which would make it impossible to see the core.

(3 @ 0.75 pts each - 2.25)

REFERENCE Dow Chemical General Description, Section 1.6.2 ANSWER J.02 (1.50)

To prevent siphoning of the reactor pool should a leak in the system occur, the suction line extends to less than 3 ft. below the top of the pit and 1/2 in. vent holes are drilled into both the suction line [0.75]

and the water-return line at a level of about one foot below the water line to break any siphon that might develop [0.75).

REFERENCE Dow Chemical General Description, Section 1.6.1 l l

\

ANSWER J.03 (1.50)

1. High-voltage Power Supply 5 ~ WM

2. Water Monitor GM Counter Circuit 6, ~iTA O --pm M C

3. Water Temperature Bridge qg% % g y n-\ o c M O d

4. Wide Range Log Channel gg Gjno no (3 of 4 @ 0.5 pts each = 1.5) Cg , L', necs TON REFERENCE \C bA.g CVWOOM '

Dow Chemical Instrumentation Section P3.1

(***** CATEGORY J CONTINUED ON NEXT PAGE *****)

J. SPECIFIC OPERATING CHARACTERISTICS Page 25 ANSWER J.04 (2.25)

Points to consider when introducing samples into the reactor are (1) the effect of the sample (experiment) on the reactivity excess of the reactor; (2) possible hazards of chemical nature (such as sudden polymerization of monomers in the high radiation field), and (3) possible explosion of the sample in the reactor during irradiation. (3 @ 0.75 pts each : 2.25)

REFERENCE Dow Chemical General Description, Section 1.11.1 ANSWER J.05 (2.00)

1. Fission chamber high voltage monitor (Iow level)

2. Source Interlock (low level) - (< 2 cps)

3. Rate of power increase (period output) - (> 3.6 DPM)

4. High level of power (not connected).

(4 @ 0.5 pts each : 2.0)

REFERENCE Dow Chemical Instrumentation Section 2.4.4 ,

ANSWER J.06 (3.00)

a. (1) Misadjustment of rod-down limit switch (2) Switch light-bulb failure (0.5) !

(0.5) .

b. (1) Rod-down switch not functioning properly (2) Switch light-bulb failure (0.5)

(0.5)

c. (1) Rod has stuck above lower limit (0.5)

(2) Rod-down switch not operating properly (0.5)

REFERENCE Dow Chemical Instrumentation, Table 2.1

(***** CATEGORY J CONTINUED ON NEXT PAGE *****)

J. SPECIFIC OPERATING CHARACTERISTICS Page 26 ANSWER J.07 (1.00)

1. A minimum-source interlock in series with UP buttons, (effectively shorts out the UP switch when the buttons are depressed, so that the rods cannot be raised in the absence of a. set minimum source count.) (0.5)

2. (In order to prevent more than one rod being raised at a time, the UP switches are arranged so that wnen one is activated it feeds) An intorlock signal to the other control rods preventing movement of more than one rod at a time. (0.5)

~

REFERENCE Dow Chemical Instrument Section 2.4.3 ANSWER J.08 (3.00)

1. When the rate wants to become more negative than -D.8 DPM [0.5]. The control rod is controlled by the rate-of power-increase circuit

[0.5].

2. If the rate is between -0.8 DPM and +0.8 DPM [0.5] the flux controller system will be controlled by the difference of the linear power channel signal and the setting of the percent demand potentiometer [0.5].

3. If the rate approaches +0.8 DPM [0.5] the control rods are governed by the rate circuit [0.5].

REFERENCE Dow Chemical Instrumentation, Section 2.4.8 ANSWER J.09 (2.00)

a. Americium-241-bery111um ( 0. 5 }- (\ . Cdy Tolvulum beryllium (Po-Pe) (G.5)

b. Americium-241-beryllium source has the advantage of long half-lifech

[. &S] and disadvantage of needing a special license' to own. it [ a&].

0. 5 u.oT ( ?S' Pc-Ec h:2 the diente:ntage of short helf lifs [.00]. 4es37

(***** CATEGORY J CONTINUED ON NEXT PAGE *****)

J. SPECIFIC OPERATING' CHARACTERISTICS Page_27' REFERENCE Dow Chemical Gensral Description, Section 1.4.3 ANSWER J.10 (1.50) 1.

2.

_Improvelongtermreliabi$ty 3.

Minimize the effect of activation Minimize the effect of corrosion (2 of 3 required @ 0.75 each = 1.5)

REFERENCE Dow Chemical General Description, Section 1.3.2

(***** END OF CATEGORY ~ J *****)

L

l E. FUEL HANDLING AND CORE PARAMETERS Page 28 )

ANSWER K.01 (2.00)

The minimum shutdown margin (with fixed experiments in place) provided by operable control' elements in the cold condition [0.5] without xenon (0.5],j '

with the most reactive of the operable control elements withdrawn [0.5],

shall be 0.35% delta k/k [0.5].

1 i

REFERENCE

'Dow Chemical Technical Specification Section F ANSWER K.02 (1.00)

Fuel elements yearly not to exceed 14 months (0.5];

Control elements every 2 years [0,5].

REFERENCE DC TS Section E ANSWER K.03 (1.00) 1.5% delta h/k (.1.0)

REFERENCE Dow Chemical Technical Specifications, Section E, pg. 3

(***** CATEGORY K. CONTINUED ON NEXT PAGE *****)

K. FUEL HANDLING AND CORE PAFAMETERS .Page 29 ANSWER K.04 (3.00)

1. A functional check that all reactor interlocks-are operable.

2. Verification that all control element drop times are less than one second. An element shall not be considered operable if its drop time exceeds one second.

3. A check that the power level safety circuits are operable.

4. Worth calibration for each control element.

(4 @ 0.5 pts each 2.0) -

The exception is that if the reactor is operating continuously, the tests shall be performed after the first shutdown if this occurs more than six months after the previous tests. (1.0)

REFERENCE Dow Chemical Tech Specs Section F ANSWER K.05 (1.50)

Regular fuel element consist of a uranium-zirconium hydride [0.25] (20%

U-235) either aluminum [0.25] or stainless steel clad [0.25] with a graphite slug located above and below the fuel moderator [0.25).

The dummy fuel element is aluminum cans containing only graphite. (0.5)

REFERENCE Dow Chemical General Description, Sections 1.4.1 and 1.4.2 ANSWER K.06 (2.00)

a. The total absolute reactivity worth of in-core experiments shall noa exceed $2.00. (This includes the potential reactivity which might result from experimental malfunction, experiment flooding or voiding removal of insertion of experiments.) (1.0)

b. Experiments having reactivity worths greater than $1.00 [0.5) shall be securely located or fastened to prevent inadvertent movement during reactor operations [0,5).

(***** CATEGORY K CONTINUED ON NEXT PAGE *****)

E. FUEL ~ HANDLING AND COBE PARAMETERS PageE30-REFERENCE

.Dow Chemical Tech Spec Section J ANSWER K.07 (3.00)

(1) Licensed SRO (2) F-ring (3) UP

(4) DOWN (5) B (6) C (6-@ 0.5 pts each = 3.0)

REFERENCE Procedure 4.3.3.4, " Loading of Reactor Core" ANSWER K.08 (2.00)

1. All fuel elements or fueled devices'shall'be. rigidly supported durint storage in a safe geometry (Keff less than 0.8 under.all conditions of moderation). (1.0)

2. Irradiated fuel elements and fueled devices shall be' stored ~in an array which will permit sufficient natural convection coolingLsuch-that the fuel elements or fuel device temperature'will not exceed design values. (1.0)

REFERENCE ,

Dow-Chemical Tech Specs Section H

(***** CATEGORY- K CONTINUED ON NEXT PAGE *****)

. K. FUEL HANDLING AND CORE PARAMETERS Page 31 ANSWER K.09 (4.00) 1.

The continuous air monitor will be fitted with an extension hose that will allow air to be drawn from the top of the reactor tank.

(1.0)

2. The reactor may be taken slowly to its maximum licensed steady-state power level or some lower value. During this time, the air monitor.

will be observed for activity, especially fission-gases.and their daughter products. If no activity is noted at fuel temperatures equivalent to those existing when the suspected leak was detected, it may be concluded that there is no fuel element damage. (1.0)

3. If activity is noted during the foregoing reactor test and this activity is suspected of being fission products, therefore indicating a fuel cladding failure, a number of fuel elements will be removed and replaced with elements not in the core during the preceeding test and the reactor will be operated as a test. The-air, monitor will be observed for activity. (l'0)

. This fuel replacement operation will be continued until either all fuel elements have been checked or the defective element found. If reactor operation at high steady-state levels (near licensed maximum) reveals no further release of radioactivity, the reactor fuel will be considered to be free from cladding failures. (1.0)

(Exact wording not necessary for full credit)

REFERENCE Dow Chemical Procedure 4.3.2 l

1 1

(***** END OF CATEGORY K *****)

', i

, L. ADMINISTRATIVE PROCEDURES. CQEDITIONS Pago 32 AND LIMITATIONS i

ANSWER L.01 (2.00)

Any incident or condition relating to the operation of the reactor which prevented or could have prevented a nuclear system from performing its safety function as described in the Technical Specifications.

REFERENCE Dow Chemical Procedures 4-41 ANSWER L.02 (3.00)

1. The experiment is temporarily terminated.

2. If Reactor Supervisor, the Experimenter, and Operator reach agreement, Reactor Supervisor will direct experiment to proceed.

3. If no agreement results, any party may request consultation with the Reactor Operations Committee.

(3 @ 1.0 pt each = 3.0)

REFERENCE Dow Chemical Administrative Procedure, Section 3.2.8 ANSWER L.03 (3.00)

a. 1. Time of Event

2. Description of Event

3. Any Action Taken

4. Results of the Action (4 @ 0.5 pts each : 2.0)

b. RED ink (0,5)

c. Underlined w/ red ink (0.5) i REFERENCE Dow Chemical Administrative Procedure Section 3.4.1

(***** CATEGORY L CONTINUED ON NEXT PAGE *****)

L. ADMINISTRATIVE PROCEDURES. CONDIT1QES Page 33 AND LIMITATIONS . ,

ANSWER L.04 (1.00)

At least two (2) people must be present within 1602 building. (0.5).

At least one person has to be a Senior Operator. (0.5)

REFERENCE Dow Administrative Procedure Section 3.4 ANSWER L.05 (3.00) -

a. The mechanical and electrical components of the reactor have been tested and found to be in satisfactory working condition,

b. The radiological safety devices positioned around the reactor have been calibrated and tested for proper operation,

c. The limits on' operating conditions, e.g., scram circuits, interlocks, and alarms, have been tested and accurately set.

(3 @ 1.0 pt each = 3.0)

REFERENCE Dow Chemical Administrative Procedure Section 3.4 ANSWER L.06 (2.25)

1. L To protect personnel working near the reactor and at the laboratory. !

2. To assure that operation of the reactor does not endanger the health of persons outside the laboratory.

3. To prevent damage to the reactor and associated facilities.

(3 @ 0.75 pts each : 2.25)

REFERENCE Dow Chemical Administrative Procedures Section 3.2

(***** CATEGORY L CONTINUED ON NEXT PAGE *****)

- - - _ - - - - - - - - --- - - _- I

. ?o L. ADMINISTRATIVE PROCEDURES. CONDITIONS AND LIMITATIONS Page 34-ANSWER L.07 (2.00)

a. Any person

b. Method 1: Activate the evacuation siren signal Method 2: Activate the Alert siren signal Method 3: Dial 1-2-3 on.the nearest telephone (3 @ 0.5 pts each = 1.5)

REFERENCE Dow Chemical Emergency Plan section 6 ANSWER L.08 (1.50)

Unclassified Unusual Event Alert (3 @ 0.5 pts each : 1.5)

REFERENCE Dow Chemical Emergency Plan, Section 3 l

ANSWER L.09 (2.00) i 120 days [1.0)

ten (10) [1.0]

REFERENCE 1 i

i Dow Chemical Administrative Procedures, pg. 3-38 I

i 1

l

(***** END OF CATEGORY L *****)

(********** END OF EXAMINATION **********) i

-1 a

TEST CROSS REFERENCE Page 1 QUESTION VALUE REFERENCE H.01 2.00 ZZZ0000001 H.02 1.50 ZZZ0000002 H.03 -2.00 ZZZ0000003 H.04 1.50 ZZZ0000004 H.05 3.00 ZZZ0000005 H.06 2.00 ZZZ0000006 H.07 2.00 ZZZ0000007 H.08 3.00 ZZZ0000008 H.09 1.00 ZZZ0000009 H.10 2.00 ZZZ0000010 20.00 I.01 2.50 ZZZ0000011 I.02 3.50 ZZZ0000012 -

I.03 1.50 ZZZ0000013 I.04 3.00 ZZZ0000014 I.05 1.50 ZZZ0000015 I.06 2.00 Z2Z0000016 I.07 2.00 ZZZ0000017 I.08 1.00 ZZZ0000018 I.09 2.00 Z220000019 I.10 1.00 ZZZ0000020 20.00 J.01 2.25 ZZZ0000021 J.02 1.50 ZZZ0000022 J.03 1.50 22Z0000023 J.04 2.25 ZZZ0000024 J.05 2.00 ZZZ0000025 J.06 3.00 ZZZ0000026 J.07 1.00 ZZZ0000027 J.08 3.00 ZZZ0000028 J.09 2.00 ZZZ0000029 J.10 1.50 ZZZ0000030 -

20.00 K.01 2.00 ZZZ0000031 K.02 1.00 ZZZ0000032 i

K.03 1.00 ZZZ0000033 K.04 3.00 ZZZ0000034 K.05 1.50 ZZZ0000035 K.06 2.00 ZZZ0000036 K.07 3.00 ZZ20000037 K.08 2.00 ZZZ0000038 K.09 4.00 ZZZ0000039 19.50 L.01 2.00 ZZZ0000040 L.02 3.00 ZZZ0000041 L.03 3.00 ZZZ0000042 I

L.04 1.00 ZZZ0000043-

.s~n TEST-CROSS REFERENCE Page: 2

_QUESTIQH VALUE . BEFERENCE_

L.05 3.00 ZZZ0000044 L.06 2.25 ZZZ0000045 L.07 2.00 ZZZ0000046 L.08 1.50 ZZZ0000047 L.09 '2.00 ZZZ0000048 19.75

___GmWD.

99.25 i

(

ML20237E152

Text

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